Think Little + family recently completed the first full year in our new home and office in Charlottesville, VA. It’s a very low energy house, but not quite as low as the Passive House standard. Over 369 days (12/19/08 to 12/22/09) we used 6,283kWh of electricity. Our energy model (using the PHPP - Passive House energy modeling tool) predicts 5,867kWh/year, so we’re running a measly 7% over the model. Not bad, eh?

Our house is 1,440 ft2 (exterior dimensions), so our “site energy intensity” is 4.4kWh/ft2 (14.9kBTU/ft2). I looked up the national averages for site energy intensity on the Architecture 2030 website, and they show 12.8kWh/ft2 (43.8kBTU/ft2) as they average for single family detached houses. That puts us at 66% lower site energy intensity than the national average.

We spring for Dominion Power’s green power program, so our rates are a little higher than standard. We spent a total of $843.98 on electricity for the year (all taxes and surcharges included). That works out to about $70/month. 

In 2010 we’ll start to sub-meter some of energy usage so we can analyze in more detail. I suspect our hot water use and our “plug loads” (TV, stereo, office equipment, phones, etc.) are running a little higher than what the model predicts.